1. Field of the Invention
The present invention relates to a semiconductor device and, more particularly, to a semiconductor device package wherein large- and small-current semiconductor chips are formed in a single package.
2. Description of the Related Art
In a conventional resin-sealed semiconductor device package for a large-current semiconductor chip, a heat-radiation fin is disposed, and a large-current semiconductor chip is placed on the fin. According to such a resin-sealed semiconductor package wherein a large-current semiconductor chip is placed on a heat-radiation fin, heat generated from the semiconductor chip can be dissipated through the heat-radiation fin to achieve a stable function of the semiconductor chip, and to prevent abnormal heating of the chip.
Conventionally, however, a region on a heat-radiation fin serves as an island region of a semiconductor chip, and only a large-current semiconductor chip is placed on the island region. A small-current semiconductor chip which generates less heat is formed in another package. These large- and small-current semiconductor chips cannot be contained in a single package for the following reason. First, since the chips are formed on the heat-radiation fin, heat is rapidly conducted, and the small-current semiconductor chip may be adversely affected by heat generation from the large-current semiconductor chip, thus degrading the characteristics of the small-current semiconductor chip. Second, a conductive adhesive is conventionally used to fix a small-current semiconductor chip to a substrate. The conductive adhesive has a poorer heat resistance than that of a solder or an AuSi eutectic for fixing a large-current semiconductor chip. In regard to this problem, it may be proposed to fix the small-current semiconductor chip to the heat-radiation fin by, e.g., a solder. However, the small-current semiconductor chip normally has a micropatterned and complicated, e.g., multi-layered, element structure. Therefore, the small-current semiconductor chip cannot withstand a high temperature generated when it is fixed by, e.g., a solder, and may be broken.
As described above, large- and small-current semiconductor chips cannot be simultaneously placed on a heat-radiation fin to be contained in a singe package, and a demand for high-integration packaging cannot be satisfied.